The present disclosure generally relates to syringes and, in particular, to a syringe for extracting the contents of a sealed vial.
Medications are often delivered in sealed vials. The medicine may be in either liquid form, and therefore ready to use, or in a dry, powdered form that requires reconstitution prior to use. In the case of a liquid medication, extraction of the liquid without introducing a gas into the vial results in a partial vacuum being created within the vial, which makes the extraction of the liquid more difficult. In the case of a dry medication, introduction of water into the vial, so as to reconstitute the medication, results in an increased pressure within the vial, which makes it difficult to introduce the water as well as presenting a hazard when extracting the reconstituted medication.
Vials are typically provided with a septum adapted for penetration by a needle. Vial adapters are available that include a needle, which is arranged to penetrate the septum of a vial, that is in fluid communication with a female needleless fitting configured to accept a needleless male fitting of a syringe. Common needleless fittings have a “Luer taper” conforming to an International Standards Organization (ISO) standard. Certain connectors have a self-sealing feature to prevent leakage of fluid from the attached vial when the syringe is decoupled from the fitting of the vial adapter. Certain vial adapters provide vent paths to the ambient environment to allow ambient air to enter the vial or allow gas to be expelled from the vial to the ambient environment. Certain vial adapters include a sealed chamber that capture gas expelled from the vial and prevent the expelled gas from passing into the ambient environment.
The non-vented syringe disclosed herein is adapted for use with a sealed vial, in various embodiments, so as to maintain a generally constant pressure within the vial while adding or removing liquid.
In certain embodiments, a syringe is disclosed that includes a plunger having a plunger tube having proximal and distal ends, a center tube coupled to the proximal end of the plunger tube and extending within the plunger tube toward the distal end, the center tube having a center passage, and a balloon disposed over the center tube and sealingly fixed to at least one of the center tube and the plunger tube. The syringe also includes a barrel having a barrel tube having proximal and distal ends and an interior configured to accept a portion of the plunger, a tip fixedly coupled to the proximal end of the barrel tube, a post fixedly attached to the tip and extending within the barrel tube toward the distal end, the tip configured to partially extend into the center passage of the plunger, and a gas passage extending from a proximal end of the tip to the distal end of the post.
In certain embodiments, a pre-filled syringe is disclosed that contains a prefill volume of a medical fluid. The syringe includes a plunger having a plunger tube having proximal and distal ends, a center tube coupled to the proximal end of the plunger tube and extending within the plunger tube toward the distal end, the center tube having a center passage, and a balloon disposed over the center tube and sealingly fixed to at least one of the center tube and the plunger tube. The balloon and the at least one of the center tube and the plunger tube form a gas volume containing a gas. The syringe also includes a barrel having a barrel tube having proximal and distal ends and an interior configured to accept a portion of the plunger, a tip fixedly coupled to the proximal end of the barrel tube, a post fixedly attached to the tip and extending within the barrel tube toward the distal end, the tip configured to partially extend into the center passage of the plunger, and a gas passage extending from a proximal end of the tip to the distal end of the post. The plunger is partially inserted into the barrel so as to form a liquid volume that contains the prefill amount of the medical fluid. The balloon is able to further expand such that the gas volume increases by at least the prefill volume so as to be able to accept gas displaced from a sealed vial when the prefill volume of medical liquid is injected into the vial.
In certain embodiments, a syringe for extracting a dose volume of a medical fluid from a sealed vial is disclosed. The syringe includes a plunger having a plunger tube having proximal and distal ends, a center tube coupled to the proximal end of the plunger tube and extending within the plunger tube toward the distal end, the center tube having a center passage, and a balloon disposed over the center tube and sealingly fixed to the proximal end of the plunger tube. The balloon and the plunger tube form a gas volume having a minimum gas capacity. The syringe also includes a barrel having a barrel tube having proximal and distal ends and an interior configured to accept a portion of the plunger, a tip fixedly coupled to the proximal end of the barrel tube, a post fixedly attached to the tip and extending within the barrel tube toward the distal end, the tip configured to partially extend into the center passage of the plunger, and a gas passage extending from a proximal end of the tip to the distal end of the post. The syringe is fully inserted into the barrel such that a liquid volume formed between the plunger and barrel is approximately zero and the gas volume contains a quantity of gas that is greater than or equal to a maximum liquid capacity of the liquid volume plus the minimum gas capacity.